Traverse control means for centerless grinders and polishers



Oct. 1, 1957 R. w. FULLER ETAL 2,807,917

TRAVERSE CONTROL MEANS FOR CENTERLESS GRINDERS AND POLISHERS I Filed April 1, 1955 5 Sheets-Sheet l Oct. 1, 1957 R. w. FULLER ET AL 2,807,917

TRAVERSE CONTROL MEANS FOR CENTERLESS GRINDERS AND POLISHERS Filed April 1, 1955 5 sheets -shee-z 2 Oct. 1, 1957 R. w. FULLER ETAL TRAVERSE CONTROL MEANS FOR CENTERLESS GRINDERS AND POLISHERS Filed April l, 1955 5 Sheets-5heet I Invenfofls:

Oct. 1, 1957 R. w. FULLER ETAL TRAVERSE CONTROL MEANS FOR CENTERLESS GRINDER-S AND POLISHERS Filed April 1, 1955 5 Sheets-Sheet 4 TRAVERSE CDNTRUL MEANS FDR CENTER- LESS GRINDERS AND POLISHERS Rufus W. Fuller, Deerfield, and Raymond A. Cole, Greenfield, Mass, assignors to Production Machine Company, Greenfield, Mass.

Application April 1, 1955, Serial No. 498,488

12 Claims. (Cl. 51-103) The present invention relates to centerless grinding and polishing equipment and particularlyto power operated means for effecting the axial feed of the work in either direction relative to the grinding element, while also rotating the Work.

In centerless grinders of the type shown in United States Patents Nos. 1,421,205; 2,277,644, and 2,536,757, a unit is employed that has a power driven work-engaging belt that is adjustable relative to the grinding element, either a belt or a wheel, as required by the diameter of the work. This unit is pivota'ble to enable the angle defined by the path of the belt and the axis of the work to be varied so that the work can be both rotated and axially moved by the belt, with the direction and rate of axial movement being determined by the extent to which the tilting of the unit has resulted in corresponding swinging of the path of the belt away from the vertical.

It will be readily appreciated that it is often necessary to pass the work more than once through a centerless grinding and polishing machine to finish it to the desired extent and that it is time and labor consuming to carry the work from one fixture back to the opposite side of the machine and then position it in the other fixture for another pass. The general objective of this invention is, accordingly, to provide power operated means to effect the axial movement of the work in one direction or the other to save such time and effort.

In accordance with the invention, power operated means connected to the unit are operable to pivot it to establish first and second angular positions of the belt relative to. the work to effect axial movement of the work in one direction or the other. Such power operated means, conveniently fluid pressure operated, has a control located to limit axial movement in either direction and to shift the unit to swing the belt from one position to the other and thus reverse the direction of travel of the Work. Such a control is conveniently electric and provided with switches which, when automatic operation is wanted, may be limit switches located in the work-supporting fixtures. Where these are of the type provided with sets of rolls, of which at least one roll of each set is mounted in a pivotable support, the invention contemplates like control of such pivotably supported rolls as is provided for the unit and its work-engaging belt.

In the accompanying drawings, there is shown an embodiment of the invention illustrating these and other of its objectives, novel features, and advantages.

In the drawings:

Fig. 1 is a front perspective view of a centerless grinding and polishing machine in accordance With the invention with a fixture at each of its sides;

Fig. 2 is an enlarged and partly sectioned view, as seen from the front of the machine, of the work feed unit;

Fig. 3 is a top plan view of that part of the machine that is shown in Fig. 2;

States Patent Fig. 4 is a side view of the subject matter of Figs. 2 and 3 as seen from the left-hand side as the machine is viewed in Fig. 1;

Fig. 5 is a schematic view of the hydraulic system for changing, relative to the axis of the work, the angularity of the pivotably supported rolls of the fixtures and of the work-engaging belt of the machine.

Fig. 6 is a similar View of the electric circuit for use with the hydraulic system; and

Fig. 7 is a schematic perspective showing of a set of fixture rolls and of the means for varying the angular V 37 thereto.

relation of the pivotably supported ones relative to the axis of the work.

In the embodiment of the invention shown in the drawings, there is indicated a work support 10 located between the grinding wheel 11 and the belt 12 to suitably support the work 13 with reference thereto. The drive for the belt 12 is indicated by the gear box 14 attached to the unit 15, and the drive shaft for the box 14 has a universal joint 16 and is itself indicated at 17 in Fig. l.

The unit 15 has a trunnion 18 in the support 19 slid able towards and away from the grinding wheel 11 on the mounting ways 20. Mounted adjacent the outer end of the support 19 is a gear box 21 housing a bevel gear 21a rotated by the hand Wheel 22 and meshing with the bevel gear 23 carried by the threaded member 24 threaded into the support 19. By means of this arrangement, the unit 15 is spaced relative to the grinding wheel 11 as required by the diameter of the work 13.

On the outer end of the trunnion 18 there is secured a gear segment 25, and it will be apparent that by turning the trunnion 18 in one direction or the other the unit 15 is pivoted to vary the angle between the path of the belt 12 and axis of the work 13. For example, if the path of the belt 12 is at right angles with respect to the axis of the work 13, the work will rotate but it does not move axially. If the path of the belt 12 is tilted from such a vertical position, the work is fed axially with its direction and rate of travel depending on the direction and extent of such tilting.

The support 19 is shown as provided with an indicator 26 with reference to which the series of 'graduations 26a on the proximate face of the unit 15 are readable. The support 19 has an arouate slot 27 proximate to the flange 28 on the trunnion 18 to receive the stud 29 connected by the flange 28 to which the unit is attached. The flange 28 is frictionally connected to the support 19 since the sleeve 30 is under pressure of the spring 31, which is adjustably tensioned by the nut 32, as may be best seen in Fig. 4.

Also carried by the exposed end of the support 19 is supporting structure 33 for the double-acting hydraulic cylinder 34 having attached to the exposed end of the stem of its piston 35 a connector 36 joining the rack The rack 37 meshes with the gear segment 25 and is slidable in the guide 38. The connector 36 freely receives a threaded member 39 attached to the cylinder 34 parallel to the axis of the cylinder 34 and provided with a pair of spaced adjustable stops 43 which enable the stroke of the piston to be adjusted to effect the desired positions of the belt 12.

While control of the fluid pressure operated means may be manually operated valves, it will be noted that usually grinding and polishing equipment includes, in addition to the centerless grinding and polishing machine, a pair of fixtures 4-1, one at each side of the machine.

Such fixtures may be of the type shown in United States Letters Patent Nos. 1,909,984 and 2,165,097, or in our co-pending application Ser. No. 455,295, filed September 20, 1954. Accordingly, the fixtures will not be detailed, but it will be noted that each is provided with a plurality of sets of work-supporting rolls generally indicated at 42 in Figs. 1 and 7. As shown in Fig. 7, each, set 42 includes two horizontally aligned rolls 43 and 44 and a supporting roll 45.

While the rolls of each set are adjustable relative to each as required by the size of the work", the means for so doing are not herein detailed. It is important to note, however, that at least where heavy work is being handled, one roll of each set, here the roll 45, is driven. In order that each driven roll 45 may share in the feed of the work 13, its yoke 46 is indicated in Fig. 7 as having a pivot 47. The drive for the rolls 45 is suggested by the shaft 48 connected to the stub shaft 49 of each roll 45 by a universal joint 50.

In such fixtures, the rolls 45 assist in the feed of the work when the angle between their path and the axis of the work is approximately the same as the angle defined by the path of the belt 12 and said work axis. When axial feed in accordance with the invention is wanted, change in the position of the rolls45 must be made when the position of the belt 12 is varied.

To accomplish this result. there are shown two doubleacting hydraulic cylinders 54, one for each fixture, each having the stem of its piston 55 pivotally connected to an arm 56 carried by the pivot 47. The arm 56 is pivotally connected to the connecting rod 57 leading to like arms 56 with which the pivots 47 of the other rolls 45 of that fixture are so provided.

The three double-acting cylinders 34 and 54 are under the control of a four-way valve 58 (see Figs. and 6) movable between first and second positions by solenoids 59 and 60, respectively. The solenoids 59 and 60 are in parallel circuits 61 and 62, respectively, provided with switches 63 and 64, respectively. These are shown as normally open limit switches, each being mounted on a fixture to limit and reverse the axial movement of the work with reference thereto.

Amotor driven pump 65 in the line 66 is shown as pumping oil from the tank 67 to the valve 58. A relief valve 68 in the line 66 is connected by a relief conduit 69 to the tank 67 to which a return conduit 70 from the valve 58 is connected.

From the valve 58 there are two conduits 71 and 72 each leading to corresponding ends of the double-acting hydraulic cylinders. When the valve 58 is positioned to connect the conduit 71 to the line 66, fiuid under pressure is delivered to the corresponding ends of the cylinders while fluid is free to escape from the other ends thereof through the conduit 72 to the return 70. Feed of the work in one direction now continues until a limit switch is engaged thus to energize the corresponding solenoid which immediately reverses the position of the valve 58 to reverse the relationship of the conduits 71 and 72 relative to the delivery and return lines 66 and 70, respectively.

From the foregoing, it will be apparent that the invention makes possible in centerless grinding and polishing equipment efficient means for controlling the direction and rate of the axial movement of the work, making possible substantial savings in time and labor and greater convenience in operation.

We claim:

1. In a centerless grinding and polishing machine, a unit including a work-engaging belt, a drive for said belt, said unit being so pivoted that the angle between the direction of travel of the belt and the axis of the work can be varied to cause the work to be axially moved as well as rotated by the belt, and power-operated means including a reciprocable stem connected to said unit and operable to pivot said unit to establish first and second angular positions of said belt relative to the work to effect axial movement of the work in opposite directions, a threaded element disposed in parallel with said stem, a pair of stops threaded thereon in spaced relationship, and a member carried by said stem and disposed between said stops for engagement therewith to limit movement of said stem.

2. In a centerless grinding and polishing machine, a unit including a work-engaging belt, a drive for said belt, said unit being so pivoted that the angle between the direction of travel of the belt and the axis of the work can be varied to cause the work to be axially moved as well as rotated by the belt, and power-operated means connected to said unit and operable to pivot it to establish first and second angular positions of said belt relative to the work to effect axial movement of the work in one direction or the other, and a control for said means located to be engaged by the work and operated by such engagement to establish limits of axial movement of said work in either direction and effective to control said means to shift said unit automatically from one position to the other when the work reaches one of said limits.

3. In a centerless grinding and polishing machine, a unit including a work-engaging belt, a drive for said belt, said unit being so pivoted that the angle between the direction of travel of the belt and the axis of the work can be varied to cause the work to be axially moved as well as rotated by the belt, fluid pressure-operated means connected to said unit and operable to pivot it to es tablish first and second angular positions of said belt relative to the work to effect axial movement of the work in one direction or the other, and "an electrically operated control for said means including a pair of switches.

4. In a centerless grinding and polishing machine, a unit including a work-engaging belt, a drive for said belt, said unit being so pivoted that the angle between the direction of travel of the belt and the axis of the work can be varied to cause the work to be axially moved as well as rotated by the belt, fluid pressure-operated means connected to said unit and operable to pivot it to establish first and second angular positions of said belt relative to the work to eifect axial movement of the work in one direction or the other, and an electrically operated control for said means including a pair of switches, one for each of said positions and located to be engaged and operated by an end of the work thus to limit its travel in either direction.

5. In a centerless grinding and polishing machine, a unit provided with a driven work-engaging belt and pivotable to enable the angle between the path of the belt and the axis of the work to be varied so that the work can be both rotated and axially moved by said belt, at least one fixture of the type having sets of worksupporting rolls of which one roll of each set includes a pivotable support by which the angle between its axis of rotation and the axis of the work can be varied, and power-operated means connected to said unit and said support and operative to pivot the unit and the support to an approximately equal extent and in the same direction to establish first and second angular positions of both the path of the belt and the path of the pivotably supported roll relative to the work.

6. In a centerless grinding and polishing machine, a unit provided with a driven work-engaging belt and pivotable to enable the angle between the path of the belt and the axis of the Work to be varied so that the work can be both rotated and axially moved by said belt, at least one fixture of the type having sets of work-supporting rolls of which one roll of each set includes a pivotable support by which the angle between its axis of rotation and the axis of the work can be varied, power-operated means connected to said unit and said support and operative to pivot the unit and the support to an approximately equal extent and in the same direction to establish first and second angular positions of both the path of the belt and the path of the pivotably supported roll relative to the work, and a control for said means engageable and operable by an end of the work.

7. In a centerless grinding and polishing machine, a unit provided with a driven work-engaging belt and pivotable to enable the angle between the path of the belt and the axis of the work to be varied so that the work can be both rotated and axially moved by said belt, at least one fixture or" the type having sets of work-supporting rolls of which one roll of each set includes a pivotable support by which the angle between its axis of rotation and the axis of the work can be varied, poweroperated means including a reciprocable stem connected to said unit and said support and operative to pivot the unit and the support to an approximately equal extent but in the same direction to establish first and second angular positions of both the path of the belt and the path of the pivotally supported roll relative to the work, a threaded element disposed in parallel with said stem, a pair of stops threaded thereon in spaced relationship, and a member carried by said stem and disposed between said stops for engagement therewith to limit movement of said stem.

8. In a centerless grinding and polishing machine, a unit provided with a driven work-engaging belt and pivotable to enable the angle between the path of the belt and the axis of the work to be varied so that the work can be both rotated and axially moved by said belt, at least one fixture of the type having sets of work-supporting rolls of which one roll of each set has a pivotable support by which the angle between its axis of rotation and the axis of the work can be varied, power-operated means connected to said unit and said support and operative to pivot the unit and the support to an approximately equal extent and in the same direction to establish first and second angular positions of both the path of the belt and the path of the pivotably supported roll relative to the work, and a control for said means located to be engaged and operated by said work to establish limits of its axial movement in either direction and effective to control said means to elfect a shift from one to the other of said positions when the work reaches one of said limits.

9. In a centerless grinding and polishing machine, a unit provided with a driven work-engaging belt and pivotable to enable the angle between the path of the belt and the axis of the work to be varied so that the work can be both rotated and axially moved by said belt, at least one fixture of the type having sets of work-supporting rolls of which one roll of each set has a pivotable support by which the angle between its axis of rotation and the axis of the work can be varied, fluid pressure-operated means connected to said unit and said support and operative to pivot the unit and the support to approximately the same extent and in the same direction to establish first and second angular positions of both the path of the belt and the path of the pivotally supported roll relative to the work to eflect direct movement thereof in one direction to the other, and an electricaly operated control operatively connected to said means and including apair of switches, one for each of said directions.

10. In a centerless grinding and polishing machine, a unit provided with a driven work-engaging belt and pivotable to enable the angle between the path of the belt and the axis of the work to be varied so that the work can be both rotated and axially moved by said belt, at least one fixture of the type having sets of work-supporting rolls of which one roll of each set has a pivotable support by which the angle between its axis of rotation and the axis of the work can be varied, fluid pressure-operated means connected to said unit and said support and operative to pivot the unit and the support to approximately the same extent and in the same direction to establish first and second angular positions of both the path of the belt and the path of the pivotally supported roll relative to the work to effect direct movement thereof in one direction to the other, and an electrically operated control operatively connected to said means, including a pair of switches, one for each direction and located to be engaged and operated by an end of the work thus to limit its travel in that direction.

11. In a centerless grinding and polishing machine, a unit intermediate the ends of said machine and provided with a driven work-engaging belt and pivotable to enable the angle between the path of the belt and the axis of the work to be varied so that the work can be both rotated and axially moved by said belt, a plurality of fixtures, one for each end of said machine, and of the type having sets of work-supporting rolls of which one roll of each set has a pivotable support by which the angle between its axis of rotation and the axis of the work can be varied, a fluid pressure-operated devices, one for said unit and one for each fixture, and operative to pivot the unit and the supports to approximately the same extent and in the same direction to establish first and second angular positions of the path of the belt and the paths of the pivotably supported rolls relative to the work to effect axial movement thereof in one direction or the other, a control valve for all of said devices and operatively connected thereto, and electrically operated means operatively connected to said valve including a pair of switches, one for each direction of travel.

12. In a centerless grinding and polishing machine, a unit intermediate the ends of said machine provided with a driven work-engaging belt and pivotable to enable the angle between the path of the belt and the axis of the work to be varied so that the work can be both rotated and axially moved by said belt, a pair of fixtures, one for each end of said machine, and of the type having sets of work-supporting rolls of which one roll of each set has a pivotable support by which the angle between its axis of rotation and the axis of the work can be varied, fluid pressure-operated devices, one for said unit and one for each fixture, and operative to pivot the unit and the support to approximately the same extent and in the same direction to establish first and second angular positions of the path of the belt and the paths of the pivotably supported rolls relative to the work to effect axial movement thereof in one direction or the other, a control valve for all of said devices and operatively connected thereto, and electrically operated means operatively connected to said valve including a pair of switches, one for each direction of travel, said switches each being located on a respective one of said fixtures and engageable by the work to define a limit of its travel relative thereto.

References Cited in the file of this patent UNITED STATES PATENTS 1,421,205 Fuller June 27, 1922 1,985,433 Turner Dec. 25, 1934 1,991,953 Nenninger Feb. 19, 1935 2,165,097 Fuller July 4, 1939 2,277,644 Howe Mar. 24, 1942 2,536,757 Macdonald Ian. 2, 1951 2,597,242 Hill May 20, 1952 

